Method of non-destructive inspection of flat membrane

Abstract

A pore diffusion type flat membrane separation apparatus X including a plurality of flat membranes 7 and a plurality of flat plate-like supports 1 arranged alternately with each other, each flat membrane 7 defining a plurality of pores and configured to separate a predetermined dispersed substance contained in a solution by a pore diffusion technique, each flat plate-like support 1 having a flow conduit 2 on one or both faces thereof. A ratio between a spatial volume of the flow conduit 2 and a membrane area of the flat membrane 7 is set from 0.04 to 0.4 cm. The flat plate-like support 1 includes, in at least two positions in a lateral face thereof, water conduits 3 in communication with the flow conduit 2 , so that flow directions of the solution in the flow conduits 2 of upper and lower flat plate-like supports 1 across the flat membrane 7 may be substantially same directions. The flat plate-like support 1 and the flat membrane 7 can be assembled with and disassembled from each other.

1 - 23 . (canceled) 
     
     
         24 . A method of non-destructive inspection of a flat membrane in order to allow reuse of a flat membrane having a plurality of pores and configured for separating a particular dispersed substance contained in a solution through pore diffusion technique, the method comprising an integrity test step for confirming that particle eliminating ability of the flat membrane has not been reduced, by means of a direct method utilizing microparticles other than noble metals. 
     
     
         25 . The method of non-destructive inspection of a flat membrane according to  claim 24 , wherein the method further comprises a dissolution eliminating step for dissolving and eliminating the microparticles, after said integrity test step. 
     
     
         26 . The method of non-destructive inspection of a flat membrane according to  claim 25 , wherein the dissolving eliminating agent employed at the dissolving eliminating step has characteristics of dissolving the microparticles used at the integrity test, without dissolving or swelling the material forming the flat membrane through a chemical reaction therewith. 
     
     
         27 . The method of non-destructive inspection of a flat membrane according to  claim 24 , wherein said microparticles comprise ferric hydroxide colloid particles. 
     
     
         28 . The method of non-destructive inspection of a flat membrane according to  claim 24 , wherein said material forming the flat membrane comprises hydrophilic polymer and said dissolving eliminating agent comprises hydrochloric acid. 
     
     
         29 . The method of non-destructive inspection of a flat membrane according to  claim 28 , wherein the hydrophilic polymer comprises regenerated cellulose.